rio: A Swiss-Army Knife for Data I/O

Streamlined data import and export by making assumptions that
the user is probably willing to make: 'import()' and 'export()' determine
the data structure from the file extension, reasonable defaults are used for
data import and export (e.g., 'stringsAsFactors=FALSE'), web-based import is
natively supported (including from SSL/HTTPS), compressed files can be read
directly without explicit decompression, and fast import packages are used where
appropriate. An additional convenience function, 'convert()', provides a simple
method for converting between file types.